The invention relates to a battery-powered lamp, and especially a lamp comprising a light source, a battery and a switch unit which are electrically interconnected.
In more specific terms, the invention relates to disposable lamps for general use. The lamps are hand-held lamps, both chargeable and non-chargeable, and of different sizes.
Ordinary lamps, particularly lamps containing replaceable batteries, light sources or other components, all have in common the problem that they corrode easily and are unreliable over a period of time. This is usually due to the penetration of moisture, resulting in corrosion of contacts between batteries, light source and switch. A result of this corrosion is that the lamp has to be shaken and knocked in order to make it work.
U.S. Pat. No. 4,303,970 discloses a lamp of the type mentioned at the beginning, which is made watertight by means of a sealed housing. The lamp also contains an elastic material, such as foam rubber. The material provides electrical and thermal insulation, but contains air, thus leading amongst other things to the risk of condensation being formed inside the lamp. Optimal protection is therefore not obtained against the formation of corrosion in the electrical connections. The lamp contains a mechanical switch which is operated from the outside via sealing means around a control spindle. This represents an additional risk of penetration of air, water and vapour and of the formation of corrosion.
An object of the invention is to provide a lamp as mentioned at the beginning, which is reliable, resistant in most environments, watertight, corrosion-resistant, robust, possessing long storage durability, resistant to impact, shock and other physical stresses, and having low production costs.
A special object of the invention is to provide a lamp of this kind which can also be operated from outside by an operating body, where the operating body, does not detract from qualities in the lamp such as reliability, resistance, watertightness, corrosion resistance, robustness and storage durability.
A further object is to provide a lamp of this kind which in addition is environmentally friendly, and/or a lamp of this kind which can be included in a return scheme.
The above objects are achieved by means of a lamp as set forth in the patent claims.